The problems of starting and hot restarting a high intensity discharge lamp are well known and numerous circuits have been developed in efforts to solve the problems associated with such lamps. Most such circuits have been developed for the purpose of operating lamps of relatively low wattage, i.e., having rated powers ranging from less than 100 to a few hundred watts. Circuits developed for this purpose have not been suitable for use with high wattage HID lamps, particularly metal halide lamps. It has been found that such lamps require higher reionization voltage and energy, more intermediate or "carry through" voltage and energy than such circuits have been able to deliver, plus increased open circuit voltage to initiate and stabilize the arc.